Eudendrium

Moura, Carlos J., 2015, The hydrozoan fauna (Cnidaria: Hydrozoa) from the peaks of the Ormonde and Gettysburg seamounts (Gorringe Bank, NE Atlantic), Zootaxa 3972 (2), pp. 148-180 : 154

Eudendrium sp.

(fig. 2G, H, I)

Material studied. Ormonde, stn 1: fertile colonies, frequent on cauli of alga Zonaria tournefortii , DBUA 1514.01, Genbank accession no. KM402031 . Ormonde, stn 3: few exemplars, delicate, unbranched and monosiphonic colonies, overgrowing cauli of Zonaria tournefortii ; hydrocauli with few annulations, DBUA 1514.07. Ormonde, stn 4: frequent on the alga Zonaria tournefortii , overgrowing other algae conjunctly with Orthopyxis integra ; DBUA 1512.02. Gettysburg, stn 5: fertile specimens; small, delicate and unbranched colonies; overgrowing Zonaria tournefortii and Aglaophenia pluma ; DBUA 1514.02. Gettysburg, stn 6: abundant on Zonaria tournefortii , fertile and monosiphonic colonies; DBUA 1514.03; Genbank accession no. KM402026 . Gettysburg, stn 7: frequent on cauli of Zonaria tournefortii , hydrocauli somewhat annulated, DBUA 1514.04. Gettysburg, stn 8: fertile, predominantly on cauli of Zonaria tournefortii , less common on hydrorhizae of Sertularella ellisii , DBUA 1514.05. Gettysburg, stn 9: abundant, on small shrimp and cauli of the alga Zonaria tournefortii , DBUA 1512.01. Gettysburg, stn 10: few colonies on cauli of Zonaria tournefortii , pedicels strongly annulated, DBUA 1514.06.

Remarks. This biological material consists of extremely small, monosiphonic and stolonal rarely branched colonies, developing sporosacs on hydranths. Perisarc is smooth, corrugated or have annulated stretches. Nematocysts identified correspond to small microbasic euryteles (5–7.4)x(2.7–3.6)Μm, r= 1.5–2.4, and large unidentified capsules on the hydranth body (10.9–14)x(4.3–7.4)Μm, r=2–2.8 ( Figs. 2 H, I)

The present taxon resembles Eudendrium album Nutting, 1898 and E. simplex Pieper, 1884 , but 16S haplotype data did not reveal any particular phylogenetic relationship with any of these species, as well as to a great variety of other Eudendrium species mainly found in the NE Atlantic and Mediterranean (Schuchert & Moura, unpublished phylogenetic analyses). Because both morphologically and molecularly, this biological material of Eudendrium is differentiated from the other herein reported, and because this is the only study reporting Eudendrium taxa in the Gorringe, this represents the first record of this inconspicuous species in the Gorringe.

The publication of 16S sequences obtained from samples of stations 1 and 6, is expected to allow a future correct taxonomic identification of this biological material.

Figures

FIGURE 2. A: Filifera indet. — polyp; Stn 9. B: Bougainvilliidae indet. — fragment of a colony; Stn 10. C, D: Amphinema cf. dinema — individual polyps detached from the colony; Stn 4. E: Eudendrium armatum — live bushy colony little exposed to sunlight; Stn 7. F: Eudendrium cf. merulum — dense tufts of well-developed monosiphonic colonies; Stn 4. G – I: Eudendrium sp. — pedicels with polyps (G); Stn 4 (left) and Stn 1 (right); small microbasic euryteles (H); large nematocysts (I). J: Coryne eximia — large colonies overgrowing a cable; Stn 4. K: Coryne sp. — part of a colony; Stn 5. Scale bars: 10 µm (H, I); 0.2 mm (A); 1 mm (B, C, D, G, K); 1 cm (F). Photo credits. C. J. Moura.